Low-voltage ride through strategy for bidirectional power electronic transformers

Authors

Xiangping Kong, Electric Power Science Research Institute, State Grid Jiangsu Electric Power Co., Ltd., Nanjing 211103 , China
Peng Li, Electric Power Science Research Institute, State Grid Jiangsu Electric Power Co., Ltd., Nanjing 211103 , China
Jiexiang Han, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 , China
Zhe Zhang, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 , China
Xianggen Yin, State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 , China

Keywords

power electronic transformer, low voltage ride through, control strategy, current instruction value

Abstract

n view of the operating characteristics of PET when the AC grid voltage sags, this paper proposes a LVRT strategy for bidirectional PET. During the voltage drop, the injected reactive power is automatically adjusted according to the positive sequence voltage drop to assist the grid voltage recovery. According to the active power of PET before the voltage sag, the level and direction of the active power are maintained as far as possible without exceeding the current limit to reduce the disturbance to the AC/DC grids. In the case of asymmetric voltage drop, the negative sequence current suppression is regarded as the supplementary method to ensure the symmetry of the injected grid current. Finally, the effectiveness of the proposed LVRT strategy is verified by the case study.

DOI

10.19781/j.issn.1673-9140.2021.02.015

First Page

124

Last Page

131

Recommended Citation

Kong, Xiangping; Li, Peng; Han, Jiexiang; Zhang, Zhe; and Yin, Xianggen (2021) "Low-voltage ride through strategy for bidirectional power electronic transformers," Journal of Electric Power Science and Technology: Vol. 36: Iss. 2, Article 15.
DOI: 10.19781/j.issn.1673-9140.2021.02.015
Available at: https://jepst.researchcommons.org/journal/vol36/iss2/15